As a method of filling a hydrogen tank of a fuel cell vehicle with hydrogen as fuel, there are known a method of compressing hydrogen at a high pressure and filling the hydrogen into a hydrogen tank, a method of liquefying hydrogen and filling the hydrogen into a hydrogen tank, and the like. When hydrogen is compressed at a high pressure and is filled into a hydrogen tank, the higher the pressure at which the hydrogen is compressed is, the more a filling amount of hydrogen can be increased, which can elongate a cruising distance of a fuel cell vehicle. On the other hand, as a pressure of hydrogen when it is supplied into a hydrogen tank and a pressure of the hydrogen filled therein increase, the hydrogen is more likely to leak during the supplying operation and to leak outside after the filling operation. Thus, a hydrogen tank capable of suitably preventing leakage of hydrogen during a supplying operation and after a filling operation has been conventionally developed.
A degree of the aforementioned leakage of hydrogen from a hydrogen tank may vary depending on an environment. In addition, there is a possibility that an amount of hydrogen, which can be filled into a hydrogen tank from outside, and an amount of hydrogen, which can be supplied from the inside of a hydrogen tank to the outside, might vary depending on an environment. Thus, in the general development of a hydrogen tank, environmental tests are carried out under various conditions such as a low temperature zone, a high temperature zone and so on. Various apparatuses have been conventionally used as a test apparatus for carrying out an environmental test of a hydrogen tank. For example, Non-Patent Document 1 discloses a test apparatus including a relatively large chamber in which a hydrogen tank environmental test can be carried out within a temperature zone of between −40° C. and 85° C.
Non-Patent Document 1: HyTReC: Hydrogen Energy Product Research and Test Center, page 5, upper left column [online], [retrieved on Jun. 5, 2015], Internet <URL:http://www.hytrec.jp/pdf/H26panfu.compressed.pdf>